I cannot thank you enough for your video on using the green fan wire plugged into the c slot to power the thermostat. I would have never thought of that in a million years. My nest was a mess. No decent power supply. The adjustment I made based on your video was done minutes before the ac tech was due to arrive for my summer ac check up. Had I not done this work around the tech would not have been able to due the check up. The standard visit for a check up is 60 dollars. The charge for diagnosis of a problem is 90 dollars. Your advise saved me 90 dollars!! Thank you so very much. Dan Las Vegas.
This tip worked for me!!!! Last night was the first night I really needed heat in the house since I installed my Nest. I was freaking out because we were cold this morning and the Nest kept saying delayed for 2:30 and the furnace wouldn't stay on for more than 60 seconds. Now... the house is getting warm with the furnace running until the room hits temperature. A most sincere thank you to you from me, my wife, my children, and my pets. We won't freeze again tonight.
That's sounds awful. Why would Nest make a system that isn't transferable from existing systems with the same electronics? Is the C wire for wifi/app control?
Amazing!!! After watching this video I was able to switch the 2 wires in a couple of minutes. It was exactly as described. I am a visual learner and the white board you used was perfect. The symptom of my Nest was it would turn on and turn off right away over and over. This fixed that. Tks so much!!!
This is a great solution for those who have only four wires running from the thermostat to the furnace/blower unit; however, it's been my experience that most electricians will use a cable with six or seven wires and just not use them all. The easiest solution is that, if you have this situation, connect the black (common) wire to the Nest, and go to the furnace/blower, and connect the black wire to the common terminal. Another solution (if you don't want to sacrifice the functionality of turning on and off the fan from the Nest) is to use your old (4-wire) thermostat cable to pull a new 6-wire thermostat cable. Securely loop individual wires form the old cable to the new one and then tape over the connect so you have a smooth surface to pass over any tight spots along the root. Go to the attic/basement/furnace closet and use the old wire to pull the new one through the wall/floor/ceiling, etc. and connect it as diagramed here.
Simple and to the point! I spent hours asking folks at Home Depot, etc, and searched the web reading about its possible to use the green wire as C wire but was confusing, wasn't sure if I need to bridge green with C or how to do it. This answered all my questions as a noob and save some serious $$ booking an HVAC "specialist" for a home visit/ thermostat install. Thank you!
Thank you. I have had my Nest set up for years, but never had cooling working. Heating has been fine. I watched 2 minutes. Went to my Nest, made the changes, and we have cooling. Thank you..... My family thanks you too....
Makes perfect sense - now to find out how to get into my damn furnace! I went up in the attic and I couldn't find the control board to save my life...all while baking in the heat. LOL
Maybe time for a new video with the Nest Power Connector? I can't seem to find much about it, but it is a pretty easy fix for my situation. The furnace has a C terminal but the house only has 2 wires to the thermostat. It hooks on at the furnace to R,W,C and then out to the original thermostat wiring and presumably makes the R wire powered all the time I suppose or however that works. Seems like a way nicer option versus a transformer and having to deal with hiding the wire.
Thank you for your helpful video with an excellent description of what to look for and how to fix the common wire problem. I was able to pull a new thermostat wire from my unit in the basement up to the thermostat and using the wiring diagram figure out the common wire and add power to my Nest thermostat. It had worked for about 2 years but with the heating system and Hot water heat, not running the fan, my battery was low on voltage. Fixed for the cost of a new wire.
@@OneHourSmartHome i installed it in the same exact way in this video. Works without any problem. Saved money from new wiring and installation charges. thank you
@@rgruenhaus an infinity thermostat is communicating. You would have to rewire the furnace to the conventional terminal block and use the r,c,y,ect terminals instead of the abcd plug infinity systems use
This is actually kinda genius. Yes we don't ever use that "fan only" function on ours and i think we just have four wires. Using the green fan wire as common is the best solution, I never would have thought of that. They sell AC adapter plugs for 20 dollars if you can't change the green wire for some reason.
Each time you mentioned the C wire and G connection it was helpful, but as you mentioned earlier a heat pump might be different so you might have wanted to say something added about the fan not being needed because the furnace turns on the fan "Except" when you have a heat pump and the fan is turned on without the furnace or compressor to circulate air when minor changes in temp are only needed which saves money!
Great video! Lucky for me the C wire from the thermostat was just left unconnected to the control board. So I just connected that using wire nut the C wire which is already going to the outside AC unit.
Sir, I have been looking at your video/issues regarding no C wire and like many, I purchased a Nest Thermostat. This issue is very prevalent on Oahu, these track homes dont usually have the C-Wire for a thermostat, to be fair because in the past we didnt need a C wire for these 20th century mercury-type thermostats, now we do... Just about about 3 months ago we finally installed after 20 years, we replaced our Rheem Central Air Unit up in the attic and the fan module in the back yard. Typically these track homes here, the builders here always put the "minimal" units to these new track homes. Anyway, we have this,"Haus-beast mode Ac Unit" now and it sounds like a jet starting up with all the cool air blowing through our large home, even to our farthest rooms in the home downstairs...nice...Sir, but again we didnt have a C-wire so the new installers weren't able to hook up my Nest Thermostat and just put our old battery thermostat for now. I really was considering your other incredible video with the plug-in transformer but to me sir, having a transformer is just so ghetto(for me) I can do what you illustrate on your other transformer video because it is so simple since I have an outlet just below the thermostat area upstairs but again to me, it just doesn't look good and it takes an outlet socket away from our daily chores and what not.......BUT Honestly Sir....I know i can do this...I just need to go up into the attic and switch out the fan wire(because frankly, for over 20 years NEVER i have used our fan option, no one has on Oahu...) and reroute it onto the C-wire on main unit in the attic and Nest....Im am a TH-camr advocate repair guy, i too also have some How To Videos to help out. Wish me luck...ill be turning off all the voltage when i make this upgrade..Mahalo...ill let you know...your video looks so painfully easy...Just follow the yellow brick road....Mahalo Again Dana
Thank you! This fixed my problem! I installed a nest e thermostat late last spring. When in cooling mode, my draft inducer fan (for heating) was turning off and on continuously when the air conditioner was running. After what you said about sometimes using the "common" wire, it turns out that I had to connect the blue wire to the "C" terminal and also to the "C" terminal on the furnace circuit board. My old t-stat did not use this wire. The nest e directions did not require me to do this. It solved my issue, no more draft inducer fan running during the cooling mode. THANKS!
I think I’m in the same boat. My 5th wire is blue and unused at the thermostat and at the furnace. I’m planning to use it as a common. There are already two white wires connected to the common screw at the furnace (probably to the AC and to the humidifier like you said). Sounds like it is okay hook up a third wire (blue) to the common screw. Sound right?
i also have a orange wire... does it go in the OB slot? i have yellow (y1), green(g), orange(ob), white(w1), blue(c), and red(rh).... do i need to swap my rh to rc?
My Nest Gen3 thermostat started experiencing low battery after 3 years of service. Originally installed with 4 wires. Battery voltage started falling under 3.6V. Lucky me, the wire between the furnace to the thermostat is 5 conductor! Connected to fifth wire to the C terminals. Now have 3.79V & 200mA.
I like your videos, they are very clear. I have a question, my air handler has two wires on the C terminal but my Nest thermostats C terminal doesn't have a wire on it, can I put a third wire on the C terminal on my air handler and run it to the C terminal on my Nest thermostat?
Very informative. Question what happen if you have a blue wire instead of yellow??, I used the blue as a yellow it work until today it gave me a message saying e75 ??
Depending on your system, you should also add a jumper wire on the control board at the furnace. This jumper wire goes between G and one other terminal depending on the system. You’ll need an 18 gauge jumper wire. • Heating/Cooling (gas/oil/propane/radiant): Jumper Y G • Cool-only: Jumper Y G • Heat-only (electric): jumper W G • Heat-only (gas/oil/propane): no jumper wire required. Also, the wiring configuration shown in this video will not work for heating/cooling system w/electric heat source. And Heat-only system with only 2-wires.
I have this exact wiring to my Nest. I bought the transformer you recommended in your other video. When I attached it to C and Rh leaving the Rc wire attached) I got an error message that there was a wire inserted into C but no power. When I check the output of the transformer it reads 25.459 volts. How do I hook up the transformer with the wiring currently in place as you show it in this video????? Thank you- and I'll send you a pot of coffee!!!!!!
Yes Sir, I went up to my attic and Ive been up there before and i know how HOT and tight spaces i had to crawl under and over the AC vent coils running all through my home. I get to the newly rheem ac we just installed about 3 months ago. I open the panel and behold...I did see all the alphabets and colored wires but BUT it didn't have your easy access to the common wire or green fan wire; in fact, (I should of taken a picture) but by the time i got to the panel i was already drenched in sweat) anyways, all the colored wires were all intact into this white plastic component that all the different colored wires were intact uniformed that you pulled off and onto these 5 little copper pricks. I was lost..HOLYS*&$. This 10k investment i just installed and with little electrical experience i have. I didn't even want to temp to play around with this great investment. So, I plugged everything back, screwed the panel back, getting out of dodge because i was sweating crazy and overheating....Sir, I really hoped it was as easy as you explained but i think the new technology with this plastic component that all the colored wires were inserted, then pushed into those copper pricks. I was hoping to do this C wire Hack this way because its more smarter and cleaner; however, i guess I am heading towards the 24v transformer route. Luckily just below about 4 feet below my thermostat is an electrical outlet where I can snake the wires down to the outlet and plug transformer into the outlet. Sad because I didn't want that nasty bulky transformer taking an outlet. Oh well...it is what it is...the blessing is that at least i went up into the attic and seen the challenges/obstacles before me and i can see I went up there and discovered I am not capable to play around with that situation and the transformer is my definite route. Thank You for all you help though, I still learned a lot from you...my capabilities, my options..Mele Kalikimaka and Maka Hiki Hou Dana SAID ALL THIS Sir, what my understanding all the wires are running the same current...Because the Green Wire to the Fan option is so WORTHLESS here on the islands and I have NEVER USED THE FAN EVER 20yrs in my home...COULD I JUST Put the Green onto the C Wire while the Green is still intact with the fan on the Furnace in the Attic, let me know thanks
I did exactly as you said. When I turned on the circuit breaker, seen the new wiring update on my nest. I tried the heat, check it’s working and air is coming out of registers. When I tried the central air conditioning, the a/c came on but not the blower! I turned off the circuit breakers, rechecked my work, everything looked good, turned on again with the same results, no blower for a/c. Do I need to check anything on the a/c compressor? Any suggestions would be welcomed!!
I have the thermostat installed into my AC unit. The heat is separate. The heat has a control unit that has all the terminals nicely labeled. But the AC unit doesn’t have a control box like that. Everything is wired directly to the relays and transformers. Any suggestion on where I could install the C/Common (ground) wire too?
Some systems don't turn the fan on in cooling without a G wire causing icing and then water leaks. If you try this fix make sure your fan works in cooling. All gas fired furnaces will turn the fan on in heat but some will not in cool.
Only two wires on a hot water boiler, can I use the new Nest thermostat without any modifications? I have the gen 3 in the house but bought a basic Thermostat today at HD and now concerned that it won’t work without another power wire? Mine are W and Rh
Question: I have an old furnace that I'm only see two cables White and black. I guess Black is power which is my R and white will be the heat and still need the C cable in order to use an smart thermostat. Is that right? Thx
I got a hot water heater with only two wires, red and black hooked to thermostat. No bus bar at heater hoked up with three zone vales each controlled by a separate thermostat. Need a C wire and need a good idea how to hook it up.
I have watched your videos many times when I first bought the Nest last winter and after adding a C wire the heater worked finally. Now that the AC is needed I’m facing issues again. The AC only comes on when I disconnect the RC wire, but then I get Error E79 and I can’t control the thermostat at all. What else can I try?!
Hi.....Hi...... I have several thermostats in my house. my nest learning thermostat works great I am trying to set up a new generation of the nest thermostat (the one that requires a c wire). My old thermostat just had a W, R, green and blue wire. I have tried the blue wire for a c wire but it didn't work. I get moving the g wire to the c and then having to do the same in the furnace. but I have never done that. Being that I have four thermostats in my house, how do I know which g wire needs to be moved? thanks
Excellent idea. However I don’t have a C terminal on my HVAC 2 stage Trane. Connected I have a W3, W2, W1, G, Y2, Y1, R, B, Yo. Open I have BK and O. Can I use my green cable connected to the G terminal to either the BK or O terminals to my WiFi C terminal? I have to add a C wire for my two stage ac to work properly. A million thanks in advance!!!
I have a new heat pump system installed, and my g-wire doesn't function as fan only. I just pulled the g-wire from thermostat to see if it was unneeded for heating and the fan coil fan never comes on with the g-wire unplugged. So apparently the information in the video only applies to certain types of systems. I have enough wires and my system works perfectly, but I was just testing the info in the video.
Because I use the fan to continue running for a few minutes at the end of the cooling cycle, I decided to use the W wire as the C wire. Yes, I will have to switch this back in the late fall, and can then use the Y wire at that point, but I won't loose the Fan feature of an extra few minutes of cool air after the cycle completes.
I have a Nest installed on my Furnace but Nest is not controlling my Humidistat because I only have a cable with 4 wires. I tried and couldn't replace the cable. Can I use a Venstar add-a-wire? Can you help me with the wiring diagram?
Say I don't have a C wire. If I want to use the fan only in the winter time...couldn't I disconnect the A/c by turning off the breaker to the A/C, and then set the thermostat to "cool"?
No. A jumper from any of the other terminals to C will cause a direct short and at best blow your 24v fuse in the furnace circuit board or at worst burn your new 200 dollar nest stat.
Hi. I have a boiler system. 2 wire to a Honeywell inline control valve. Colors Red and White. I have an addition wire in wall, it's an older boiler. No C wire terminal block. What else can I attach it to? Thanks
I just installed a 3rd generation Nest. My battery says it's low. So I have 4 wires in yellow, green, red (RH), and white, but with Nest telling me my battery is low, after watching your other video, do I have to connect the C wire or am I going to find the battery will run out? In other words, is there power coming from any of the other wires to the C terminal to help charge it? I do see extra blue wire ends attached on the line on both ends (not installed), I could install it, but do I need too?
I have a green wire not being used only white and red. Can’t I just attach the green with the red at the thermostat and the other end of the green to the c at the thermostat?
I have a Trane Air conditioning system and I was not able to switch the G wire to the C location. Due to the fact that there are separate transformers inside the AC system. Nothing like a motherboard I could see.
I have a Nest E thermostat but only 2 wires coming in so no power, am thinking of adding and external transformer but the transformer has 2 wires . One will go into the C terminal, but where does the other wire go, the Nest E has no other R labeled slots? Do I just cap the wire? Great presentation. Thanks for any help.
Nice explination i have 29.6vlts at the termostat 2nd issue my air handler has relays i didnt see a board. I called nest i was told too much volts at the termostat do i conect a common wire and how thanks
great information but looking at some other video and some are saying to use a jumper to Y and G on the control board @ the Furnace any help on that ...
Hi, Thank you for the info, I live in a hot climate city so I don't really need the heat function... Is it ok to use this solution on the W wire rather than the fan ? Thank you in advance..
you can use it on any wire just know that whatever wire you move to the C terminal you will lose that functionality, all wires are the same its just a matter of what terminal its connected to dont let the colors intimidate you. Hope this helps!
You are the man! Thank you so much! Your explanation was amazing! I have one question, my nest thermostat doesn’t activate the furnace above 24 degrees Celsius, 75 degrees Fahrenheit. It takes it sweet time to get there. I have a two stage 80k btu brand new keeprite furnace. All the wires are connected, or at least I think they are. An hvac guy installed everything, I didn’t do it myself. He blames the nest thermostat 3rd generation at says it’s a piece of garbage. Is it me? Is it the thermostat or is it him? I’m trying to figure this all out. Hence I’m here and subscribed to you because you explain everything so simply. Please let me know your thoughts. Thank you in advance!
So I have low battery issue on my google nest learning thermostat. I have extra 3 wires that are behind my thermostat and its end in the furnace is not connected to anything so I can just use any one of them to connect to C terminal in the furnace and then same colour into my thermostat. I guess that will solve my low battery issue correct?
Hi. We have continuous power outage and every time I need to recharge the battery via usb. Wires on nest are connected as follow: Y1, G, OB, C and Rh. I bought a transformer to have continuous power but every time I install I loose the 24V common. Please note that the transformer cables are replacing the C and Rh wires
I have a modular home. My furnace has no control board. It has a red,black,greeen and white wire. These wires are connected to the thermostat wires with wire nuts. I see no option for a common wire ?? The home is only 3 years old. I pulled all panels off the furnace I see relays etc but no circuit board
You can add a common wire transformer like this : amzn.to/2UEwQHZ and watch this video: th-cam.com/video/gahPxCcPDto/w-d-xo.html let me know if you have any other questions.
Nest Thermostate "Low Battery" and thermostate shuts down. No C or Common wire. I ran a wire from the ground wire in a light switch just under the thermostate to the C terminal in the Nest thermostate and my system (furnace and central air) now works. Battery voltage is now 3.915 and lin went from 40 mA to 200 mA.
i don't have a C connection on the furnace. There is a 24V transformer. can I connect a wire to C on the transformer to the terminal block to create a C connection?
Very good. Just one thing. Several other sites explain this workaround too. They also note to put a jumper wire between Y and G on the Furnace Control Panel. I see you did not though. Can you clarify if you need to do this or not?
@@OneHourSmartHome No disrespect intended. Here are two different sites that say you do need to. So just asking again or can you explain why no need please? malekservice.com/need-c-wire-thermostat/ m.th-cam.com/video/nki-65gtvac/w-d-xo.html
Help, Please... All of a sudden, the RH is missing? thus the unit will not come on and eventually the nest goes dead as the battery dies. Nothing has changed but , it just happened. The other units are wired exactly the same with the exact same nest (3 total) and work fine. In the past it was the floater, but not this time. To be certain, I bipassed the floater. Rh still not "connected" all of a sudden. Your thoughts please.
I cannot thank you enough for your video on using the green fan wire plugged into the c slot to power the thermostat. I would have never thought of that in a million years. My nest was a mess. No decent power supply. The adjustment I made based on your video was done minutes before the ac tech was due to arrive for my summer ac check up. Had I not done this work around the tech would not have been able to due the check up. The standard visit for a check up is 60 dollars. The charge for diagnosis of a problem is 90 dollars. Your advise saved me 90 dollars!! Thank you so very much. Dan Las Vegas.
This tip worked for me!!!! Last night was the first night I really needed heat in the house since I installed my Nest. I was freaking out because we were cold this morning and the Nest kept saying delayed for 2:30 and the furnace wouldn't stay on for more than 60 seconds. Now... the house is getting warm with the furnace running until the room hits temperature. A most sincere thank you to you from me, my wife, my children, and my pets. We won't freeze again tonight.
That's sounds awful. Why would Nest make a system that isn't transferable from existing systems with the same electronics? Is the C wire for wifi/app control?
Amazing!!! After watching this video I was able to switch the 2 wires in a couple of minutes. It was exactly as described. I am a visual learner and the white board you used was perfect. The symptom of my Nest was it would turn on and turn off right away over and over. This fixed that. Tks so much!!!
This is a great solution for those who have only four wires running from the thermostat to the furnace/blower unit; however, it's been my experience that most electricians will use a cable with six or seven wires and just not use them all. The easiest solution is that, if you have this situation, connect the black (common) wire to the Nest, and go to the furnace/blower, and connect the black wire to the common terminal. Another solution (if you don't want to sacrifice the functionality of turning on and off the fan from the Nest) is to use your old (4-wire) thermostat cable to pull a new 6-wire thermostat cable. Securely loop individual wires form the old cable to the new one and then tape over the connect so you have a smooth surface to pass over any tight spots along the root. Go to the attic/basement/furnace closet and use the old wire to pull the new one through the wall/floor/ceiling, etc. and connect it as diagramed here.
Nice solution, sir! Might you be a fellow IT tech who has fished a few Ethernet wires in his day?
I watched 20 videos before this one. This video answered everything in a short time.
Simple and to the point! I spent hours asking folks at Home Depot, etc, and searched the web reading about its possible to use the green wire as C wire but was confusing, wasn't sure if I need to bridge green with C or how to do it. This answered all my questions as a noob and save some serious $$ booking an HVAC "specialist" for a home visit/ thermostat install. Thank you!
Finally a fix for my Nest to keep the A/C from short-cycling. Thank you.
I was ready to break some walls, you’re a life saver.
Lmao.. same here
Great explanation! Was so confused with the "cooling delayed for x amount of time." This was quick, easy and it worked!😁
Thank you for saving me money. As a bonus, my upstairs is no longer a few degrees warmer than the surface of the sun.
Lol, thanks for watching!
1 steaged 2nd steaged Y,iY2 c common g 24 vpk
W,1w2 heatar
Thanks this was alto off help I had 5 wire so I just added it from the furnace to the c terminal
Thank you. I have had my Nest set up for years, but never had cooling working. Heating has been fine. I watched 2 minutes. Went to my Nest, made the changes, and we have cooling. Thank you..... My family thanks you too....
Great to hear!
Watched this and had to figure out that the previous owner had swapped the brown wire so we're all set. Thanks for the info, we've got our Nest back!
Glad it helped
Thanks so much for the clarity and such an easy fix. Took me less than 5 minutes to complete. PERFECT!!!!
You saved me from a headache lol very well explained. Thanks bud
Thank you so much for this video it helped me set up my new smart thermostat without a c wire.
I bought the 24 v transformer/common wire after seeing one of your other videos additionally to talking with my Hvac guy
Glad we could help, this is the transformer:th-cam.com/video/gahPxCcPDto/w-d-xo.html and the other video: th-cam.com/video/gahPxCcPDto/w-d-xo.html
Thanks... all other videos didn’t address only 1 Red wire connection location. 👍🏼
Really helpful. I wouldn't have considered doing this unless it was this easy. It made sense and seems to have worked. Thanks!
Glad it helped!
It worked!! Took just a few minutes to figure it out after watching your video. Thanks for making this video it was very helpful.
Thaaaaaaank youuuuu!! Going to try this in the am. Video is sooo simple to follow! I’m Living on space heaters in Winnipeg atm brrr 🥶 ❄️ 🧊 ⛄️
Makes perfect sense - now to find out how to get into my damn furnace! I went up in the attic and I couldn't find the control board to save my life...all while baking in the heat. LOL
Maybe time for a new video with the Nest Power Connector? I can't seem to find much about it, but it is a pretty easy fix for my situation. The furnace has a C terminal but the house only has 2 wires to the thermostat. It hooks on at the furnace to R,W,C and then out to the original thermostat wiring and presumably makes the R wire powered all the time I suppose or however that works. Seems like a way nicer option versus a transformer and having to deal with hiding the wire.
Thank you for your helpful video with an excellent description of what to look for and how to fix the common wire problem. I was able to pull a new thermostat wire from my unit in the basement up to the thermostat and using the wiring diagram figure out the common wire and add power to my Nest thermostat. It had worked for about 2 years but with the heating system and Hot water heat, not running the fan, my battery was low on voltage. Fixed for the cost of a new wire.
I’m going to install Nest Thermostat E today following this video. Hope all goes good. I’ll comment after installation.
Good to know, glad we could help.
@@OneHourSmartHome i installed it in the same exact way in this video. Works without any problem. Saved money from new wiring and installation charges. thank you
@@anandcosta Thanks for the update and happy to hear it worked for you!
Wow this is brilliant. We started using the air for the first time with the nest and have had problems so I’ll have to try this.
Glad to hear it helped! Thanks for the comment.
I am going to be replacing an infinity thermostat from 2007 to a wifi thermostat. Do you know if the infinity thermostat uses a C wire?
@@rgruenhaus an infinity thermostat is communicating. You would have to rewire the furnace to the conventional terminal block and use the r,c,y,ect terminals instead of the abcd plug infinity systems use
This was the fix I needed.
This is actually kinda genius. Yes we don't ever use that "fan only" function on ours and i think we just have four wires. Using the green fan wire as common is the best solution, I never would have thought of that. They sell AC adapter plugs for 20 dollars if you can't change the green wire for some reason.
Thanks for this video and advice!
You're a great teacher
Each time you mentioned the C wire and G connection it was helpful, but as you mentioned earlier a heat pump might be different so you might have wanted to say something added about the fan not being needed because the furnace turns on the fan "Except" when you have a heat pump and the fan is turned on without the furnace or compressor to circulate air when minor changes in temp are only needed which saves money!
Robert thanks for the insightful comment. We're adding a video on heat pumps also.
Excellent video, thanks so much
Thanks for the easy fix and simple explanation!
🙏I was about to return my thermostat. Make sure to get some tech money from google😀
This helped so much thanks!!!
This use of the fan wire is solid "More than one way to skin a 🐈" type information.
Great video! Lucky for me the C wire from the thermostat was just left unconnected to the control board. So I just connected that using wire nut the C wire which is already going to the outside AC unit.
Glad it helped!
Sir, I have been looking at your video/issues regarding no C wire and like many, I purchased a Nest Thermostat. This issue is very prevalent on Oahu, these track homes dont usually have the C-Wire for a thermostat, to be fair because in the past we didnt need a C wire for these 20th century mercury-type thermostats, now we do...
Just about about 3 months ago we finally installed after 20 years, we replaced our Rheem Central Air Unit up in the attic and the fan module in the back yard. Typically these track homes here, the builders here always put the "minimal" units to these new track homes. Anyway, we have this,"Haus-beast mode Ac Unit" now and it sounds like a jet starting up with all the cool air blowing through our large home, even to our farthest rooms in the home downstairs...nice...Sir, but again we didnt have a C-wire so the new installers weren't able to hook up my Nest Thermostat and just put our old battery thermostat for now.
I really was considering your other incredible video with the plug-in transformer but to me sir, having a transformer is just so ghetto(for me) I can do what you illustrate on your other transformer video because it is so simple since I have an outlet just below the thermostat area upstairs but again to me, it just doesn't look good and it takes an outlet socket away from our daily chores and what not.......BUT Honestly Sir....I know i can do this...I just need to go up into the attic and switch out the fan wire(because frankly, for over 20 years NEVER i have used our fan option, no one has on Oahu...) and reroute it onto the C-wire on main unit in the attic and Nest....Im am a TH-camr advocate repair guy, i too also have some How To Videos to help out. Wish me luck...ill be turning off all the voltage when i make this upgrade..Mahalo...ill let you know...your video looks so painfully easy...Just follow the yellow brick road....Mahalo Again Dana
Works great! Exactly what I needed.
Thank you! This fixed my problem! I installed a nest e thermostat late last spring. When in cooling mode, my draft inducer fan (for heating) was turning off and on continuously when the air conditioner was running. After what you said about sometimes using the "common" wire, it turns out that I had to connect the blue wire to the "C" terminal and also to the "C" terminal on the furnace circuit board. My old t-stat did not use this wire. The nest e directions did not require me to do this. It solved my issue, no more draft inducer fan running during the cooling mode. THANKS!
Awesome! Thanks for sharing the comment as this can help other people with the same issue. Thanks for subscribing.
I think I’m in the same boat. My 5th wire is blue and unused at the thermostat and at the furnace. I’m planning to use it as a common. There are already two white wires connected to the common screw at the furnace (probably to the AC and to the humidifier like you said). Sounds like it is okay hook up a third wire (blue) to the common screw. Sound right?
i also have a orange wire... does it go in the OB slot? i have yellow (y1), green(g), orange(ob), white(w1), blue(c), and red(rh).... do i need to swap my rh to rc?
I also have an orange wire. Any solutions here?
@@honeymu5tard302 my setup was… y1- yellow G- green OB-orange Rh-red C-blue w1- white
My Nest Gen3 thermostat started experiencing low battery after 3 years of service.
Originally installed with 4 wires. Battery voltage started falling under 3.6V.
Lucky me, the wire between the furnace to the thermostat is 5 conductor!
Connected to fifth wire to the C terminals. Now have 3.79V & 200mA.
I like your videos, they are very clear. I have a question, my air handler has two wires on the C terminal but my Nest thermostats C terminal doesn't have a wire on it, can I put a third wire on the C terminal on my air handler and run it to the C terminal on my Nest thermostat?
Very informative. Question what happen if you have a blue wire instead of yellow??, I used the blue as a yellow it work until today it gave me a message saying e75 ??
Excellent excellent explanation.
Great job, thanks bra!
Very good tip!! I was trying to figure out what I was going to do, now I know!
Glad I could help.
Depending on your system, you should also add a jumper wire on the control board at the furnace. This jumper wire goes between G and one other terminal depending on the system. You’ll need an 18 gauge jumper wire.
• Heating/Cooling (gas/oil/propane/radiant): Jumper Y G
• Cool-only: Jumper Y G
• Heat-only (electric): jumper W G
• Heat-only (gas/oil/propane): no jumper wire required.
Also, the wiring configuration shown in this video will not work for heating/cooling system w/electric heat source. And Heat-only system with only 2-wires.
Great instruction James! Keep it up.
Thank You!
Gracias señor. thank you this video really help me get my new term... install
Glad it helped
Great tip to steal the G (Fan) wire!
Glad I could help.
hi good video but i have 5 wires Rh,Rc,W,Y,G, how can i stup the C wire in the nest thank
I have this exact wiring to my Nest. I bought the transformer you recommended in your other video. When I attached it to C and Rh leaving the Rc wire attached) I got an error message that there was a wire inserted into C but no power. When I check the output of the transformer it reads 25.459 volts. How do I hook up the transformer with the wiring currently in place as you show it in this video????? Thank you- and I'll send you a pot of coffee!!!!!!
Yes Sir, I went up to my attic and Ive been up there before and i know how HOT and tight spaces i had to crawl under and over the AC vent coils running all through my home. I get to the newly rheem ac we just installed about 3 months ago. I open the panel and behold...I did see all the alphabets and colored wires but BUT it didn't have your easy access to the common wire or green fan wire; in fact, (I should of taken a picture) but by the time i got to the panel i was already drenched in sweat) anyways, all the colored wires were all intact into this white plastic component that all the different colored wires were intact uniformed that you pulled off and onto these 5 little copper pricks. I was lost..HOLYS*&$. This 10k investment i just installed and with little electrical experience i have. I didn't even want to temp to play around with this great investment. So, I plugged everything back, screwed the panel back, getting out of dodge because i was sweating crazy and overheating....Sir, I really hoped it was as easy as you explained but i think the new technology with this plastic component that all the colored wires were inserted, then pushed into those copper pricks. I was hoping to do this C wire Hack this way because its more smarter and cleaner; however, i guess I am heading towards the 24v transformer route. Luckily just below about 4 feet below my thermostat is an electrical outlet where I can snake the wires down to the outlet and plug transformer into the outlet. Sad because I didn't want that nasty bulky transformer taking an outlet. Oh well...it is what it is...the blessing is that at least i went up into the attic and seen the challenges/obstacles before me and i can see I went up there and discovered I am not capable to play around with that situation and the transformer is my definite route. Thank You for all you help though, I still learned a lot from you...my capabilities, my options..Mele Kalikimaka and Maka Hiki Hou Dana
SAID ALL THIS Sir, what my understanding all the wires are running the same current...Because the Green Wire to the Fan option is so WORTHLESS here on the islands and I have NEVER USED THE FAN EVER 20yrs in my home...COULD I JUST Put the Green onto the C Wire while the Green is still intact with the fan on the Furnace in the Attic, let me know thanks
No. If you get any feedback voltage from the board to G it will send it back to the stat and burn the stat board.
I did exactly as you said. When I turned on the circuit breaker, seen the new wiring update on my nest. I tried the heat, check it’s working and air is coming out of registers. When I tried the central air conditioning, the a/c came on but not the blower! I turned off the circuit breakers, rechecked my work, everything looked good, turned on again with the same results, no blower for a/c. Do I need to check anything on the a/c compressor? Any suggestions would be welcomed!!
Any idea on how to connect / workaround and setup nest thermostat with a 240v system ?
Worked like a champ! Thanks!!
I have the thermostat installed into my AC unit. The heat is separate. The heat has a control unit that has all the terminals nicely labeled. But the AC unit doesn’t have a control box like that. Everything is wired directly to the relays and transformers. Any suggestion on where I could install the C/Common (ground) wire too?
Some systems don't turn the fan on in cooling without a G wire causing icing and then water leaks. If you try this fix make sure your fan works in cooling. All gas fired furnaces will turn the fan on in heat but some will not in cool.
Very nice presentation. 👍
Some suggest to put a jumper wire between Y & G terminals at furnace side. What do you think about the jumper?
My Nest doesn't charge on its base. Will changing the wire from G to C as outlined here, enable the charging?
Only two wires on a hot water boiler, can I use the new Nest thermostat without any modifications? I have the gen 3 in the house but bought a basic Thermostat today at HD and now concerned that it won’t work without another power wire? Mine are W and Rh
What if I have two power supplies (one from air handler and one from boiler )?
Great video and instructions
Thank you! Nice and clear explanation. Much appreciated.
Glad we could help!
Question: I have an old furnace that I'm only see two cables White and black. I guess Black is power which is my R and white will be the heat and still need the C cable in order to use an smart thermostat. Is that right? Thx
I got a hot water heater with only two wires, red and black hooked to thermostat. No bus bar at heater hoked up with three zone vales each controlled by a separate thermostat. Need a C wire and need a good idea how to hook it up.
What if I have a hvac from 1980. Since the C wire need 24v is there another place I can tap into?
I have watched your videos many times when I first bought the Nest last winter and after adding a C wire the heater worked finally. Now that the AC is needed I’m facing issues again. The AC only comes on when I disconnect the RC wire, but then I get Error E79 and I can’t control the thermostat at all. What else can I try?!
What will tell the fan to turn on if you have no g wire.? Should I run a jumper between w and g to make sure fan turn on when it calls for heat???
Hi.....Hi...... I have several thermostats in my house. my nest learning thermostat works great I am trying to set up a new generation of the nest thermostat (the one that requires a c wire). My old thermostat just had a W, R, green and blue wire. I have tried the blue wire for a c wire but it didn't work. I get moving the g wire to the c and then having to do the same in the furnace. but I have never done that. Being that I have four thermostats in my house, how do I know which g wire needs to be moved? thanks
Excellent idea. However I don’t have a C terminal on my HVAC 2 stage Trane. Connected I have a W3, W2, W1, G, Y2, Y1, R, B, Yo. Open I have BK and O. Can I use my green cable connected to the G terminal to either the BK or O terminals to my WiFi C terminal? I have to add a C wire for my two stage ac to work properly. A million thanks in advance!!!
Good explanation and clear. Keep it up!
Thanks!
I have a new heat pump system installed, and my g-wire doesn't function as fan only. I just pulled the g-wire from thermostat to see if it was unneeded for heating and the fan coil fan never comes on with the g-wire unplugged. So apparently the information in the video only applies to certain types of systems. I have enough wires and my system works perfectly, but I was just testing the info in the video.
Because I use the fan to continue running for a few minutes at the end of the cooling cycle, I decided to use the W wire as the C wire. Yes, I will have to switch this back in the late fall, and can then use the Y wire at that point, but I won't loose the Fan feature of an extra few minutes of cool air after the cycle completes.
thnks for the info. have problem my furnace board don'g have a c connector what can do
Glad to help!
I have a Nest installed on my Furnace but Nest is not controlling my Humidistat because I only have a cable with 4 wires. I tried and couldn't replace the cable.
Can I use a Venstar add-a-wire? Can you help me with the wiring diagram?
Worked perfectly. Thanks!
Glad I could help!
Say I don't have a C wire. If I want to use the fan only in the winter time...couldn't I disconnect the A/c by turning off the breaker to the A/C, and then set the thermostat to "cool"?
Brilliant and simple. Thank you :)
Can you put a jumper between G and C (if there are other wire on C already)?
No. A jumper from any of the other terminals to C will cause a direct short and at best blow your 24v fuse in the furnace circuit board or at worst burn your new 200 dollar nest stat.
No, you cant jumper. The c wire goes in one terminal for providing power and the g wire is fan control.
@@OneHourSmartHome thank you
Is there any need to put a jumper wire from Y terminal to G terminal?
Hi. I have a boiler system. 2 wire to a Honeywell inline control valve. Colors Red and White. I have an addition wire in wall, it's an older boiler. No C wire terminal block. What else can I attach it to? Thanks
Thank you ! It helped to fix issue , without spending any 💵
Glad I could help!
I just installed a 3rd generation Nest. My battery says it's low. So I have 4 wires in yellow, green, red (RH), and white, but with Nest telling me my battery is low, after watching your other video, do I have to connect the C wire or am I going to find the battery will run out? In other words, is there power coming from any of the other wires to the C terminal to help charge it? I do see extra blue wire ends attached on the line on both ends (not installed), I could install it, but do I need too?
I have a green wire not being used only white and red. Can’t I just attach the green with the red at the thermostat and the other end of the green to the c at the thermostat?
I have a Trane Air conditioning system and I was not able to switch the G wire to the C location. Due to the fact that there are separate transformers inside the AC system. Nothing like a motherboard I could see.
I have a Nest E thermostat but only 2 wires coming in so no power, am thinking of adding and external transformer but the transformer has 2 wires . One will go into the C terminal, but where does the other wire go, the Nest E has no other R labeled slots?
Do I just cap the wire?
Great presentation.
Thanks for any help.
Nice explination i have 29.6vlts at the termostat 2nd issue my air handler has relays i didnt see a board. I called nest i was told too much volts at the termostat do i conect a common wire and how thanks
great information but looking at some other video and some are saying to use a jumper to Y and G on the control board @ the Furnace any help on that ...
Hi,
Thank you for the info, I live in a hot climate city so I don't really need the heat function...
Is it ok to use this solution on the W wire rather than the fan ?
Thank you in advance..
you can use it on any wire just know that whatever wire you move to the C terminal you will lose that functionality, all wires are the same its just a matter of what terminal its connected to dont let the colors intimidate you. Hope this helps!
You are the man! Thank you so much! Your explanation was amazing! I have one question, my nest thermostat doesn’t activate the furnace above 24 degrees Celsius, 75 degrees Fahrenheit. It takes it sweet time to get there. I have a two stage 80k btu brand new keeprite furnace. All the wires are connected, or at least I think they are. An hvac guy installed everything, I didn’t do it myself. He blames the nest thermostat 3rd generation at says it’s a piece of garbage. Is it me? Is it the thermostat or is it him? I’m trying to figure this all out. Hence I’m here and subscribed to you because you explain everything so simply. Please let me know your thoughts. Thank you in advance!
Awesome but what if u live in a apt.?
So I have low battery issue on my google nest learning thermostat. I have extra 3 wires that are behind my thermostat and its end in the furnace is not connected to anything so I can just use any one of them to connect to C terminal in the furnace and then same colour into my thermostat. I guess that will solve my low battery issue correct?
Hi. We have continuous power outage and every time I need to recharge the battery via usb. Wires on nest are connected as follow: Y1, G, OB, C and Rh. I bought a transformer to have continuous power but every time I install I loose the 24V common. Please note that the transformer cables are replacing the C and Rh wires
I have a modular home. My furnace has no control board. It has a red,black,greeen and white wire. These wires are connected to the thermostat wires with wire nuts. I see no option for a common wire ?? The home is only 3 years old. I pulled all panels off the furnace I see relays etc but no circuit board
You can add a common wire transformer like this : amzn.to/2UEwQHZ and watch this video: th-cam.com/video/gahPxCcPDto/w-d-xo.html let me know if you have any other questions.
Nest Thermostate "Low Battery" and thermostate shuts down. No C or Common wire. I ran a wire from the ground wire in a light switch just under the thermostate to the C terminal in the Nest thermostate and my system (furnace and central air) now works. Battery voltage is now 3.915 and lin went from 40 mA to 200 mA.
i don't have a C connection on the furnace. There is a 24V transformer. can I connect a wire to C on the transformer to the terminal block to create a C connection?
Very good. Just one thing. Several other sites explain this workaround too. They also note to put a jumper wire between Y and G on the Furnace Control Panel. I see you did not though. Can you clarify if you need to do this or not?
You shouldn't need a jumper on the Y and G terminal.
@@OneHourSmartHome No disrespect intended. Here are two different sites that say you do need to. So just asking again or can you explain why no need please?
malekservice.com/need-c-wire-thermostat/
m.th-cam.com/video/nki-65gtvac/w-d-xo.html
Help, Please... All of a sudden, the RH is missing? thus the unit will not come on and eventually the nest goes dead as the battery dies. Nothing has changed but , it just happened. The other units are wired exactly the same with the exact same nest (3 total) and work fine. In the past it was the floater, but not this time. To be certain, I bipassed the floater. Rh still not "connected"
all of a sudden.
Your thoughts please.
Great video, very helpful!!!!!! Right to the point!!
Glad we could help! Thanks for the comment.